I've looked into this a little bit so here's what I've found. The difference between alcohol and gas as far as specific gravity is 25-30% less for alcohol, so you need to increase your jet size about that. Eastman has a kit to coat the inside of the gas tank about $100. Because of the difference in specific gravity you will lose about that much in mileage. You can get back part of what you lose in mileage by increasing compression ratio. Tom Langdon told me that for every two points you raise your compression ratio (i.e. 8.0:1 to 10.0:1) you will get back 8% in power and 7% in efficiency (mpg). I've seen various numbers on the octane rating of E85, 103, 105... I computed the octane from numbers I got from Wikipedia and came up with 117. E85 is selling for about 20% less than regular gas in the midwest from what I've been told. Since you lose mpg running it, and consumer economics, I doubt that it will ever sell for more. If you raise your compression by four points you get back about half the difference. I've just about finished rebuilding a 292 short block with zero deck clearance, with the stock head I'll get 10.0:1 compression, with a 194 head I'll get 12.0:1.
I need more information on what the alcohol is going to try and eat. I've heard about the tank and gas lines and dissolving deposits in the fuel system. First I've heard about hard anodizing the carb. I've also heard comments about rubber fuel lines.
Larry
